TY  - JOUR
JF  - Geophysical Research Letters
KW  - Lithospheric stress-field
KW  -  Driving forces
KW  -  Convection
KW  -  Motion
KW  -  Tectosphere
KW  -  Tomography
KW  -  Topography
KW  -  Viscosity
A1  - Conrad, CP
A1  - Lithgow-Bertelloni, C
ID  - discovery146995
N2  - The shear tractions that mantle flow exerts on the base of Earth's lithosphere contribute to plate-driving forces and lithospheric stresses. We investigate the sensitivity of these tractions to sub-lithospheric viscosity variations by comparing shear tractions computed from a mantle flow model featuring laterally-varying lithosphere and asthenosphere viscosity with those from a model with layered viscosity. Lateral viscosity variations generally do not change the direction of shear tractions, but deeply penetrating continental roots increase traction magnitudes by a factor of 2-5 compared to 100 km thick lithosphere. A low-viscosity asthenosphere decreases traction magnitudes by a smaller amount, and is important only if >100 km thick. Increased plate-mantle coupling beneath thick continental lithosphere may increase plate-driving forces, surface deformation, and mantle-derived lithospheric stresses in these regions. By contrast, a low-viscosity asthenosphere does not decouple the lithosphere from mantle flow, highlighting the geological importance of mantle tractions on the lithosphere.
SN  - 0094-8276
PB  - AMER GEOPHYSICAL UNION
UR  - http://dx.doi.org/10.1029/2005GL025621
N1  - Copyright 2006 by the American Geophysical Union
IS  - 5
TI  - Influence of continental roots and asthenosphere on plate-mantle coupling
AV  - public
Y1  - 2006/03/15/
VL  - 33
ER  -